1. Field of the Invention
This invention relates to a control method for a storage control apparatus, and a storage control apparatus.
2. Description of the Related Art
The amount of data handled by computer systems has increased enormously over the recent past. To effectively use and manage the huge quantities of data in a data center or the like, storage systems are provided. Such systems are designed to connect a storage device such as a disk array device or the like and an information processing device by a network, usually for exclusive use, to realize high speed, and to have access to the storage apparatus and its associated massive amount of storage space. The network commonly used to realize high-speed data transfer is a Storage Area Network (SAN), which is a network configured in communication apparatuses based on the fibre channel protocol. Another type of apparatus has been developed, referred to as Network Attached Storage (NAS), which allows access with file designations from an information processing device through a Local Area Network (LAN), using a Transmission Control Protocol/Internet Protocol (TCP/IP). The network connects the storage devices and the information processing device.
As the importance of the data handled by a storage system increases, reliability and availability of the data in the system become increasingly important. In response, to improve the reliability and availability of storage systems, a technology referred to as cluster storage has been developed, for example, as shown in JP-A-2002-351703. The cluster is configured, for example, as a group of information processing devices which provides fail-over to other members of the cluster when needed. This enables improving the reliability and availability of the storage system.
Another issue in modern storage systems is that if processing of a data input/output request being transmitted from an information processing device is made without any change, regardless of a failure of the information processing device, data in the storage device may be lost, or there may be an administrative mismatch of data, or other problems will occur. To enhance the reliability and availability of the storage system, it is also important to prevent problems that occur on the information processing device from impacting the quality of the data in the storage device.
This invention provides an improved storage control apparatus, and an improved method of controlling a storage control apparatus, which improves the reliability of the storage system and the availability of the data therein.